Add today, high up the list of those iconic images of the 1960s, that of Peter Fonda in floral shirt and outrageous sideburns, riding free on his Harley, to a soundtrack of Steppenwolf’s Born to be Wild.

John Kay’s growl was a battle hymn for those “looking for adventure” along the open road down which Wyatt, Billy and George (Fonda, Dennis Hopper and Jack Nicholson) unleashed themselves. And they, Fonda above all, represented the quintessence of that era – its creative tumult, idealism, loss and self-absorption – on screen.

Easy Rider was the 35mm celluloid Woodstock; it was the reckless hippy gypsies’ manifesto of endless asphalt ribbon. Of course it has dated, the fact that the road trip was funded by smuggling cocaine from Mexico has lost its romance, as has the whole – in retrospect grotesque – glorification of drugs. On the other hand, Fonda’s film was the first to portray LSD as a horror show. Either way, people my age watched Fonda on the edge of our seats, wanting to be him; to feel that liberation through wind and speed across America’s boundless space, to be by that camp fire. But we didn’t want to be attacked by club-wielding rednecks, we didn’t want the bad trip, and certainly didn’t want to be gunned down on a lonely road.

In this way, Fonda was the cautionary tale in all that summer of peace and love. He took the 1960s dream out of the comfort zone, away from Haight Ashbury, Sunset Boulevard and Greenwich Village, out into real America – where it twisted into nightmare. While the Grateful Dead, Jefferson Airplane, Buffalo Springfield and the Byrds (who recorded The Ballad of Easy Rider) proclaimed the new liberation within the mind and on the streets, Fonda tested it to the limit, and his character Wyatt paid the price with his life.

This was Fonda’s message, and genius: whether he foresaw it or not, he presented in his most famous film not a dawning of the age of Aquarius, but a bitterly riven America.

Feel familiar? Though my generation watched Fonda’s open-road strike for freedom drop-jawed, we now behold the vindication of his darker vision. As I write this, the descendants of those thugs who battered George, then shot Wyatt and Billy to death converge on Portland, Oregon, for a far-right rally where they can spit their same murderous hate in a bastion of liberal tolerance – what they perceive as Fonda-land, on the west coast.

At a deeper level, Fonda’s hitting the open road was more than geographical and even cultural. It was existential: like Jack Kerouac, even Albert Camus, Fonda encouraged, inspired and – in another way – was responsible for that sense of self-imposed “un-belonging” that has propelled my life (for what that is worth) and, more importantly, some of the best writing and music of my generation.

A sense of exile in the land where you were born; a sense of identity that only feels at home when it is nowhere, or at least in between one place and another.

Fonda practised this in his real life: he often said that motorcycles were his “only focus”; he loved sailing. Fonda’s candid memoir Don’t Tell Dad is a litany of confrontations with authority, in which he usually comes out on top – but their telling oozes a certain sorrow, albeit magnificent.

He is honest about his own career on the snakes-and-ladders board of the movie industry, and the writing on his family deepens this existential solitude; he is raw on the appalling relationship with his famous father, Henry, and the gradual disappearance of his mother from any role in his life.

Easy Rider was of course not Fonda’s only film. Ulee’s Gold revitalised his career in 1997. The Perfect Age of Rock ’n’ Roll, directed by Scott Rosenbaum, explores the uncanny fact that Jimi Hendrix, Janis Joplin, Brian Jones and Jim Morrison all died at 27. I’d put Wyatt around that age too.

But Fonda made it beyond that, to 79; farewell but not goodbye, Easy Rider, and thanks from all of us, wherever we are.